Gas compressor



April 24, 1951 J. H. ANDERSON 2,550,515

GAS COMPRESSOR iled Nov. 19, 1947 INVENTOR JMHWDM.

ms ATTORNEY.

Patented Apr. 24, 1951 GAS COMPRESSOR James H. Anderson, Easton, Pa., assignor to Ingersoll-Rand Company, New York, N. Y., a corporation of New Jersey Application November 19, 1947, Serial No. 786,949

i. This invention relates to compressors, and more particularly to 'a gas compressor in which the force of a pressure wave created by an explosion in one end fof a chamber is utilized directly to compressa'charge of airinthe oppositeend of the chamber.

- One objectof the invention is to provide a gas compressor of simple construction in which a pressure wave of an explosion, rather than the explosion gas therefrom, acts directly to compress a charge of air.

' Another object isto introduce the exhaust gas from an explosion into the air compressed by a pressure wave of the explosion.

A further object is to construct a gas compressor wherein the length of the work chamber and the frequency of the explosion pressure waves therein are so chosen that, within the chamber, the pressure waves travel approximately one half wave length, or a multiple thereof.

Another object is to utilize the reflected part of a pressure wave of an explosion for compressing the next succeeding explosive charge in a chamber. p I

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawings in which similar numerals refer to similar parts,

" Figure 1 is' a longitudinal elevation of a gas compressor constructed in accordance with the practice of the invention, and

Figure 2 is a sectional View of the gas compressor ShOWiIIg the position of the devices when the compressor is at rest.

Referring more particularly to the drawings, the gas compressor, designated in general by 20, is supported in its operating position by supports 2| attached to a base plate 22. The compressor comprises a tubular casing 23 having a chamber 24 in which both an explosion occurs and a separate charge of air is compressed. For the sake of simplicity and clarity in the following description, the chamber 24 is to be considered divided into two parts, an explosion end 29 and a compression end 30.

Combustion-supporting air is conveyed to the chamber 24 by a conduit 25 and 'an inlet port 26 situated at one end wall 21 of the casing 23. A valve 28, normally maintained. in an unseated position with respect to the port 26, acts responsively to the pressure in the explosion end 29 of the chamber'to' control the flow of combustion-supportingair thereinto. The valve may be of the poppet type and its stem l9 has a nice 1 Claim. (Cl. 230-72J sliding fit through an aperture in a projection 3| in the inlet conduit 25. The valve 28 is biased in its unseated position by the action of a stem-circling spring 32 against the projection 3i near the end wall 21, by a suitable pump 34 con-' nected into the fuel line 35. For igniting the explosive mixture thus formed in the chamber, an ignition device, in this case a spark plug 36, projects into the casing 23 through an aperture at a point substantially opposite the spray nozzle. The coordinated operation of the fuel pump 34 and the spark plug 36 may be accomplished by any one of a number of well known means (not shown).

Located approximately one half the pressure wave length from the point of explosion in the casing and in substantially the same transverse plane of the casing 23, are an air inlet port 31 and a discharge port 38 whichserve as a means for introducing air into the compression end3ll of the chamber 24 and for exhausting the air after it has been compressed.

The flow of air through the inlet port 31 is controlled by an air inlet valve 39 which acts responsively to pressure waves of the explosion in the chamber 24 and is normally held unseated in the port 31. structurally, the valve 39 may be similar to the valve 28 and its stem 40 has a sliding fit through an aperture in a projection 43 in an air inlet pipe 4| to permit endwise movement therethrough. The valve 39 is normally held open by a spring 42 encircling the valve stem 40 and acting against the projection 43 and an end 44 of the valve.

To prevent the leak-back of compressed gases into the chamber 24, a check valve. 45 normally held seated in the port 38 is unseated by a predetermined pressure of the compressed air in the chamber, thus opening the port 38 to allow the compressed air to pass into the discharge pipe 46. A spring 48, encircling a valve stem 41 attached to the valve, acts between a valve guide 49 in the pipe 46 and one end of the valve 45 to hold the valve in a seated position in the port 38.

The inner side of an end wall 58 of the casing 23 serves as a reflecting surface 5| to reflect the explosion pressure waves back toward their point of origin, and thus, each reflected wave will compress a succeeding charge of explosive mixture in the explosion end 29 of the chamber 24. The length of the chamber 24 is so chosen and the frequency of the explosions are so regulated that, when the pressure wave from an explosion is at its peak in one end of the chamber 24, it is simultaneously at its lowest value in the other end. It will be readily understood, therefore, that the length of the chamber must approximate one half of a pressure wave length, or some odd multiple thereof.

At the beginning of an operating cycle of the compressor, combustion-supporting air is admitted into the explosion end 29 of the chamber 24- through the port 26. Fuel is then injected into the air and the resulting explosive mixture is ignited by a spark produced at the spark plug 36. Ignition of the explosive charge forces the valve 28 to seat in the port 25 and creates an explosion pressure wave which moves along the chamber 24 toward the compression end 39 thereof. As the explosion Wave moves from the explosion end of the chamber a low pressure area is created allowing the valve 28 to again open and admit a new charge of combustion-supporting air.

The pressure wave passes through the chamber toward the compression end much faster than the exhaust gas from the explosion. As the peak of the wave reaches the discharge port 38, it compresses a charge of air in the compression end 30 ofthe chamber 24- which, in turn, forces open the valve 45 allowing the compressed air to pass into the discharge pipe 46. After the compressed air is discharged, the wave is reflected from the reflecting surface 5| toward its point of origin. A low pressure area is thus created in the compression end 36 of the chamber 24 causing the air inlet valve 39 to unseat and allow a new charge of air to pass into the chamber 26. The reflected pressure wave moving toward the point of explosion compresses the new charge of explosive mixture causing the valve 28 to seat in the port 26. Further operation of the compressor is a repetition of the above described cycle.

It. will be understood that, since the pressure wave from an explosion travels along the chamber 24 faster than the exhaust gas from the same explosion, anumber of additional cycles are carried through before the exhaust gas from the original explosion will eventually be forced out of the discharge port 38 along with a charge of compressed air. In other words, the pressure wave travels through a number of exhaust gas charges in the chamber before it finally compresses the charge of air therein. One exhaust gas charge is added in the explosion end of the chamber and one such charge is discharged through the port 38 every cycle, but there are, of course, numerous other exhaust gas charges between these two.

It will be apparent from the foregoing description that changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claim.

I claim:

A gas compressor, comprising a casing defining a chamber and having an inlet port therefor, a pressure responsive valve to seat in the inlet port for valving combustion-supporting air into the chamber, means for injecting fuel into the combustion-supporting air to produce an explosive mixture, means for igniting the explosive mixture, an air inlet port in the casing at a distance approximating one half of an explosion wave length from the point of explosion in the chamber, a valve acting directly in -response'to a pressure wave of the explosion for valving air through the air inlet port into the chamber, a discharge port located in the casingin substantially the same transverse plane as theair inlet port, a check valve acting responsively to the pressure wave of the explosion for controlling the flow through the discharge port of the air com.- pressed by' the pressure 'wave and exhaust gas from the explosion, and a reflecting surface on the casing serving to reflect the pressure wave of one explosion to compress the next succeeding charge of explosive mixture.

JAMES H. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent: 

